Solid catalyst component and catalyst for olefin polymerization, process for producing olefin polymer and process for producing solid catalyst component for olefin polymerization

ABSTRACT

There are provided: 
     (I) a solid catalyst component (A-1) for olefin polymerization, which is obtained by a process comprising the step of contacting: 
     (a-1) a carrier of carboxyl group-carrying polymer particles having an average particle diameter of from 1 to 300 μm, and 
     (b) a transition metal compound of the number 4 group of metals in the periodic table of elements; 
     (II) a catalyst for olefin polymerization, which is obtained by a process comprising the step of contacting: 
     (A-1) the above solid catalyst component, and 
     (B) at least one compound selected from the group consisting of an organoaluminum compound and an organoaluminumoxy compound; 
     (III) a process for producing an olefin polymer, which comprises the step of polymerizing an olefin in the presence of the above catalyst; and 
     (IV) a process for producing the above solid catalyst component (A-1), which comprises the step of contacting: 
     (a-1) the above carrier, and 
     (b) the above transition metal compound.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional Application of U.S. application Ser.No. 09/661,296, filed Sep. 13, 2000, now U.S. Pat. No. 6,544,921, claimpriority from Japanese Application No. 11-274076, filed Sep. 28, 1999,the disclosures of which are hereby incorporated by reference in theirentirety.

FIELD OF THE INVENTION

The present invention relates to a solid catalyst component for olefinpolymerization, a catalyst for olefin polymerization, a process forproducing an olefin polymer and a process for producing a solid catalystcomponent for olefin polymerization.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 5,409,875 discloses a solid catalyst component, which is anew olefin polymerization catalyst component, and which is obtained bysupporting a magnesium compound and a titanium compound on a carrier ofa functional group-carrying polymer. More specifically, the patentdiscloses a process for producing an ethylene based polymer with use ofa catalyst, which catalyst is obtained by a process comprising thefollowing steps (i) to (v):

(i) dissolving an ethylene-unsaturated carboxylic acid copolymer in anorganic solvent,

(ii) adding a poor solvent to the resulting solution to precipitate theethylene-unsaturated carboxylic acid copolymer,

(iii) separating the precipitated copolymer by filtration, drying theseparated copolymer, and then pulverizing the dried copolymer,

(iv) contacting the pulverized copolymer, an organomagnesium compoundand a transition metal compound with one another to obtain a solidcatalyst component, and

(v) contacting the obtained solid catalyst component with anorganoaluminum compound to obtain a catalyst.

The patent also discloses that the obtained catalyst can exhibit a highactivity in the polymerization of olefin, particularly in thecopolymerization of ethylene with an α-olefin.

However, the above-mentioned catalyst is not sufficient from a viewpointof obtaining an olefin polymer having a low content of lower molecularweight polymers and/or low crystallinity polymers. In addition, theabove-mentioned solid catalyst component has a problem such that itcontains a lot of fine powders to make its particle size distributionbroad, and as a result, the obtained ethylene-α-olefin copolymer is notsatisfactory in its powder properties.

SUMMARY OF THE INVENTION

Objects of the present invention are to provide (i) a solid catalystcomponent for olefin polymerization, (ii) a highly active catalyst forolefin polymerization, (iii) a process for producing an olefin polymer,particularly a copolymer of ethylene with an α-olefin, and (iv) aprocess for producing a solid catalyst component for olefinpolymerization, according to which an olefin polymer having an extremelylow content of lower molecular weight polymers and/or low crystallinitypolymers, and an olefin polymer having superior powder properties can beobtained.

The present inventors have undertaken extensive studies to achieve theobjects. As a result, it has been found that the objects can be achievedby providing (i) a solid catalyst component (A-1) for olefinpolymerization, which is obtained from a combination of a carrier (a-1)of carboxyl group-carrying polymer powder having a specific averageparticle size and a transition metal compound (b) of the number 4 groupof metals in the periodic table of elements, and (ii) a solid catalystcomponent (A-2) for olefin polymerization, which is obtained from acombination of a carboxyl group-carrying polymer carrier (a-2), atransition metal compound (b) of the number 4 group of metals in theperiodic table of elements and a phenol compound (c). Thereby, thepresent invention has been obtained.

The present invention provides a solid catalyst component (A-1) forolefin polymerization, which is obtained by a process comprising thestep of contacting:

(a-1) a carrier of carboxyl group-carrying polymer particles having anaverage particle diameter of from 1 to 300 μm, and

(b) a transition metal compound of the number 4 group of metals in theperiodic table of elements.

The present invention further provides a catalyst for olefinpolymerization, which is obtained by a process comprising the step ofcontacting:

(A-1) the above-mentioned solid catalyst component, and

(B) at least one compound selected from the group consisting of anorganoaluminum compound and an organoaluminumoxy compound.

The present invention further provides a process for producing an olefinpolymer, which comprises the step of polymerizing an olefin in thepresence of the above-mentioned catalyst.

The present invention further provides a process for producing a solidcatalyst component (A-1) for olefin polymerization, which comprises thestep of contacting:

(a-1) a carrier of carboxyl group-carrying polymer particles having anaverage particle diameter of from 1 to 300 μm, and

(b) a transition metal compound of the number 4 group of metals in theperiodic table of elements.

The present invention further provides a solid catalyst component (A-2)for olefin polymerization, which is obtained by a process comprising thestep of contacting:

(a-2) a carboxyl group-carrying polymer carrier,

(b) a transition metal compound of the number 4 group of metals in theperiodic table of elements, and

(c) a phenol compound.

The present invention further provides a catalyst for olefinpolymerization, which is obtained by a process comprising the step ofcontacting:

(A-2) the above-mentioned solid catalyst component, and

(B) at least one compound selected from the group consisting of anorganoaluminum compound and an organoaluminumoxy compound.

The present invention further provides a process for producing an olefinpolymer, which comprises the step of polymerizing an olefin in thepresence of the above-mentioned catalyst.

The present invention further provides a process for producing a solidcatalyst component (A-1) for olefin polymerization, which comprises thestep of contacting:

(a-2) a carboxyl group-carrying polymer carrier,

(b) a transition metal compound of the number 4 group of metals in theperiodic table of elements, and

(c) a phenol compound.

DETAILED DESCRIPTION OF THE INVENTION

(a) Carrier

Examples of a preferable polymer as a carrier used in the presentinvention are (i) a copolymer having carboxyl group-carrying unsaturatedmonomer units, and (ii) a carboxyl group-carrying polymer, whichcarboxyl groups are introduced to a polymer by a chemical or physicalmethod. Among these polymers, the copolymer having carboxylgroup-carrying unsaturated monomer units is more preferred.

As examples of the carboxyl group-carrying unsaturated monomer,unsaturated carboxylic acids such as acrylic acid and methacrylic acidare enumerated. Of these, acrylic acid is preferred.

Preferred copolymers having carboxyl group-carrying unsaturated monomerunits are those having units of the carboxyl group-carrying unsaturatedmonomer and units of a comonomer selected from the group consisting ofethylene, propylene and styrene. Examples of such copolymers areethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer,propylene-acrylic acid copolymer, propylene-methacrylic acid copolymer,styrene-acrylic acid copolymer and styrene-methacrylic acid copolymer.Among these copolymers, preferred are those having ethylene units,propylene units or styrene units as a main component, more preferred arethose having from 49.9 to 0.1% by weight of the carboxyl group-carryingunsaturated monomer units, and from 50.1 to 99.9% by weight of ethyleneunits, propylene units or styrene units, and much more preferred arethose having from 30 to 1% by weight of the carboxyl group-carryingunsaturated monomer units, and from 70 to 99% by weight of ethyleneunits, propylene units or styrene units, provided that the total weightof the copolymer is assigned to be 100% by weight. Among thesecopolymers, copolymers having from 20 to 5% by weight of acrylic acidunits or methacrylic acid units and from 80 to 95% by weight of ethyleneunits are particularly preferred.

Preferred polymers used to introduce carboxyl groups by a chemical orphysical method are those having ethylene, propylene or styrene units.More preferred polymers are ethylene homopolymer, propylene homopolymer,styrene homopolymer and copolymers having ethylene, propylene or styreneunits as a main component. Much more preferred polymers are those havingfrom 50.1 to 100% by weight of ethylene, propylene or styrene units andfrom 49.9 to 0% by weight of α-olefin units, provided that the totalweight of the polymer is assigned to be 100% by weight. Specificexamples of the polymer are polyethylene, ethylene-α-olefin copolymer,polypropylene, propylene-ethylene copolymer, propylene-butene-1copolymer and polystyrene.

The chemical or physical method for introducing carboxyl groups is notlimited, and may be any one known in the art. For example, there areenumerated:

(1) a process wherein a halogenated styrene units-carrying polymer suchas a styrene-bromostyrene copolymer is treated with an organic alkalimetal compound such as n-BuLi, and the resulting product is subjected toreaction with carbon monoxide, thereby obtaining astyrene-carboxylstyrene copolymer, and

(2) a process wherein a polyolefin such as polypropylene and a carboxylgroup-carrying unsaturated monomer such as acrylic acid are melt-kneadedin the presence of an organic peroxide to obtain acrylic acid-modifiedpolypropylene.

The carboxyl group-carrying unsaturated monomer used in the process (2)may be those mentioned above. Preferred unsaturated monomers are acrylicacid and maleic anhydride. When an acid anhydride such as maleicanhydride is used, it is recommendable to subject the melt-kneadedproduct to hydrolysis.

Examples of the carboxyl group-carrying polymers, which carboxyl groupsare introduced by a chemical or physical method, arestyrene-carboxystyrene copolymer, acrylic acid-modified polyethylene,acrylic acid-modified polypropylene, acrylic acid-modified polystyrene,maleic acid-modified polyethylene, maleic acid-modified polypropylene,maleic acid-modified polystyrene, maleic anhydride-modifiedpolyethylene, maleic anhydride-modified polypropylene, maleicanhydride-modified polystyrene, a hydrolysis product of maleicanhydride-modified polyethylene, a hydrolysis product of maleicanhydride-modified polypropylene and a hydrolysis product of maleicanhydride-modified polystyrene.

The above-mentioned carrier may be used singly or in a mixture of two ormore, or may be used in combination with other polymers in a manner suchthat the objects of the present invention is not impaired.

An average particle diameter of the carrier is from 1 to 300 μm,preferably from 3 to 200 μm, and more preferably from 5 to 80 μm, forthe production of the solid catalyst component (A-1). For the productionof the solid catalyst component (A-2), the average particle diameter ofthe carrier is not limited, but it is preferably from 1 to 300 μm, morepreferably from 3 to 200 μm, and much more preferably from 5 to 80 μm. Astandard deviation of particle diameter distribution of the carrier ispreferably from 0.1 to 50 μm, more preferably from 1 to 30 μm, and muchmore preferably from 3 to 20 μm. By using a carrier having a relativelyuniform particle diameter, the content of lower molecular weightpolymers and/or low crystallinity polymers in the obtained olefinpolymer can be decreased, and moreover powder properties of the obtainedolefin polymer can be made superior. The term, “average particlediameter” mentioned above means that measured by mixing the carrier withwater or an alcohol to form a slurry, followed by measurement with aparticle size measuring apparatus such as COULTER MULTISIZER. Here, thevalues relating to the average particle diameter and standard deviationof particle diameter distribution are by weight distribution. A shape ofthe carrier is preferably spherical, nearly spherical or elliptical.

As the carrier, commercially available polymer particles may be used.Alternatively, the carrier may be produced from a carboxylgroup-carrying polymer. As the production method thereof, for example,there is enumerated a process wherein a carboxyl group-carrying polymer,a polar solvent which does not completely dissolve said polymer and asurface active agent are mixed with one another under stirring, whichprocess makes use of a dispersion technique disclosed in U.S. Pat. Nos.3,422,049 and 3,432,483. A temperature for the production thereof ispreferably not lower than a melting point of the carboxyl group-carryingpolymer, so far as the polymer is not subjected to thermaldecomposition, and a pressure is usually from atmospheric pressure to250 atm. As the polar solvent which does not completely dissolve thecarboxyl group-carrying polymer, water and a mixed solvent mainlycomposed of water are particularly preferable. As the surface activeagent, block copolymers of ethylene oxide and propylene oxide areexemplified. The polymer particles produced according to the processmentioned above are also commercially available.

These polymer particles mentioned above are frequently contaminated withimpurities such as surface active agents and those by-produced in thecourse of production thereof, and therefore it is recommendable to washthem with an organic solvent to remove the impurities from a viewpointof polymerization activity of the catalyst in accordance with thepresent invention. As a process for washing them to remove theimpurities, for example, there is enumerated a process wherein thepolymer particles (those having an average particle diameter of from 1to 300 μm, when the solid catalyst component (A-1) is produced) arestirred in an organic solvent for 1 minute to 10 hours to form a slurry,and the particles separated from the slurry by filtration are driedunder reduced pressure at 5 to 60° C. for 10 minutes to 10 hours. Thethus obtained polymer particles are superior to those obtained bydissolving the carboxyl group-carrying polymer in a good solvent,followed by precipitation with use of a poor solvent, from a viewpointsuch that the impurities can be removed to a higher degree and theoriginal shape of the polymer particles before the removal of impuritiescan be maintained.

The organic solvent used for washing the polymer particles is a solventwhich does not completely dissolve the polymer particles. Specificexamples of the solvent are ketone solvents such as acetone, methylethyl ketone and methyl isobutyl ketone; nitrile solvents such asacetonitrile; aliphatic hydrocarbon solvents such as pentane, hexane,heptane, octane and decane; aromatic hydrocarbon solvents such asbenzene, toluene and xylene; alicyclic hydrocarbon solvents such ascyclohexane and cyclopentane; halogenated hydrocarbon solvents such as1,2-dichloroethane and monochlorobenzene; and ether solvents such asdiethyl ether and tetrahydrofuran. Of these, ketone solvents arepreferred, and acetone is particularly preferred from an economicalpoint of view.

The above-mentioned washing to remove the impurities with the organicsolvent can be carried out preferably under conditions such that thepolymer particles do not dissolve in the organic solvent to maintain theoriginal shape thereof, and a temperature is usually from −30 to 120°C., preferably from 0 to 100° C., and more preferably from 20 to 80° C.

(b) Transition Metal Compound

Examples of the transition metal compound of the 4 group metal of theperiodic table of the elements used in the present invention aretitanium compounds, zirconium compounds and hafnium compounds. Of these,titanium compounds are preferred. Among the titanium compounds,preferred compounds are those represented by the following formula.

 Ti(OR¹)_(n)X_(4-n)

wherein Ti is a titanium atom, O is an oxygen atom, R¹ is an alkyl grouphaving 1 to 4 carbon atoms, X is a chlorine atom, a bromine atom or aniodine atom, and n is 0 or an integer of 1 to 3.

Specific examples of the titanium compounds represented by the aboveformula are tetrahalogeno titanium compounds such as titaniumtetrachloride, titanium tetrabromide and titanium tetraiodide;trihalogeno alkoxytitanium compounds such as methoxytitaniumtrichloride, ethoxytitanium trichloride, butoxytitanium trichloride,phenoxytitanium trichloride and ethoxytitanium tribromide; dihalogenodialkoxytitanium compounds such as dimethoxytitanium dichloride,diethoxytitanium dichloride, dibutoxytitanium dichloride,diphenoxytitanium dichloride and diethoxytitanium dibromide;monohalogeno trialkoxytitanium compounds such as trimethoxytitaniumchloride, triethoxytitanium chloride, tributoxytitanium chloride,triphenoxytitanium chloride and triethoxytitanium bromide; andtetraalkoxytitanium compounds such as tetramethoxytitanium,tetraethoxytitanium and tetraphenoxytitanium. Of these, tetrahalogenotitanium compounds are preferred, and titanium tetrachloride isparticularly preferred.

(c) Phenol Compound

Unsubstituted or substituted phenol compounds can be used as the phenolcompounds used in the present invention. Among the substituted phenolcompounds, phenol compounds having a substituent at least at 2-positionare preferred, and those having substituents at least at 2- and6-positions are particularly preferred. Preferred substituents are ahalogen atom, and alkyl, aralkyl, aryl, silyl, alkoxy, aralkoxy, aryloxyand silyloxy groups, which groups may be substituted with a halogenatom.

Specific examples of the phenol compound are 2-substituted phenols suchas 2-methylphenol, 2-ethylphenol, 2-n-butylphenol, 2-isobutylphenol,2-t-butylphenol, 2-n-propylphenol, 2-isopropylphenol, 2-phenyphenol,2-fluorophenol, 2-chlorophenol and 2-bromophenol; 2,6-disubstitutedphenols such as 2,6-dimethylphenol, 2,6-diethylphenol,2,6-di-n-butylphenol, 2,6-diisobutylphenol, 2,6-di-t-butylphenol,2,6-di-n-propylphenol, 2,6-diisopropylphenol, 2,6-diphenylphenol,2,6-difluorophenol, 2,6-dichlorophenol and 2,6-dibromophenol; and2,6,X-trisubstituted phenols (X is at least one number selected from 3,4 and 5) such as 2,4,6-trimethylphenol, 2,6-di-t-butyl-4-methylphenoland pentafluorophenol. Among these phenol compounds, preferred are2-methylphenol, 2-ethylphenol, 2-n-butylphenol, 2-isobutylphenol,2-t-butylphenol, 2-n-propylphenol, 2-isopropylphenol, 2-phenylphenol,2,6-dimethylphenol, 2,6-diethylphenol, 2,6-di-n-butylphenol,2,6-diisobutylphenol, 2,6-di-t-butylphenol, 2,6-di-n-propylphenol,2,6-diisopropylphenol and 2,6-diphenylphenol. Further preferred phenolcompounds are 2-substituted phenols, 2,6-disubstituted phenols and2,6,X-trisubstituted phenols (X is as defined above), wherein thesubstituent is a branch-carrying alkyl, cycloalkyl or aryl group.

(A) Solid Catalyst Component for Olefin Polymerization

The solid catalyst component (A) for olefin polymerization in accordancewith the present invention is:

(A-1) a solid catalyst component for olefin polymerization, which isobtained by a process comprising the step of contacting:

(a-1) a carrier of carboxyl group-carrying polymer particles having anaverage particle diameter of from 1 to 300 μm with

(b) a transition metal compound of the number 4 group of metals in theperiodic table of elements; or

(A-2) a solid catalyst component for olefin polymerization, which isobtained by a process comprising the step of contacting:

(a-2) a carboxyl group-carrying polymer carrier,

(b) a transition metal compound of the number 4 group of metals in theperiodic table of elements and

(c) a phenol compound with one another.

From a viewpoint of obtaining an olefin polymer having a lower contentof lower molecular weight polymers and/or low crystallinity polymers,the solid catalyst component (A-2) is better than the solid catalystcomponent (A-1). Incidentally, in the production of solid catalystcomponent (A) for olefin polymerization in accordance with the presentinvention, if an organometal compound of the number 1, 2 or 13 group ofmetals in the periodic table of elements is used, the lower molecularweight polymers are increasingly produced, and therefore such a compoundcannot be used.

In the production of solid catalyst component (A-2), contacting order ofrespective ingredients (a-2), (b) and (c) is not limited. It ispreferred to carry out a first contact of the transition metal compound(b) with the phenol compound (c) and then a second contact of the firstcontact product with the carrier (a-2) in this order. It is allowable tocarry out the first contact and the second contact successively.However, it is recommendable to wash the first contact product with asolvent prior to carrying out the second contact, and further to washthe second contact product with a solvent. Contacting time for eachcontact is not particularly limited, and usually from 5 minutes to 24hours.

Respective ingredients (a-1), (a-2), (b) and (c) used for the productionof solid catalyst component (A) are used preferably in a slurry state,which is formed through dispersion in a solvent. Examples of such asolvent are aliphatic hydrocarbons such as pentane, hexane, heptane,octane and decane; aromatic hydrocarbons such as benzene, toluene andxylene; alicyclic hydrocarbons such as cyclohexane and cyclopentane;halogenated hydrocarbons such as 1,2-dichloroethane andmonochlorobenzene; and ether compounds such as diethyl ether, dibutylether, diisoamyl ether and tetrahydrofuran. Of these, aliphatichydrocarbons and aromatic hydrocarbons are preferred, and hexane,heptane, octane, toluene and xylene are more preferred.

It is recommendable to carry out the production of solid catalystcomponent (A) under atmosphere of an inert gas such as nitrogen andargon at a temperature, at which the original shape of the polymercarrier can be maintained. The temperature is usually from −30 to 120°C., preferably from 0 to 100° C., and more preferably from 20 to 80° C.

With respect to a proportion of respective ingredients used for theproduction of solid catalyst component (A), a proportion (molar ratio)of the transition metal compound (b) to the carboxyl group in thecarrier (a-1) or (a-2) is usually from 0.1 to 100 times, and preferablyfrom 0.1 to 10 times. A proportion (molar ratio) of the phenol compound(c) to the transition metal compound (b) is usually from 0.1 to 100times, and preferably from 0.1 to 10 times. The obtained solid catalystcomponent (A) is preferably placed in a cool and dark storage underatmosphere of an inert gas such as nitrogen and argon.

(B) Organoaluminum Compound and Organoaluminumoxy Compound

The “organoaluminum compound” used in the present invention means acompound having at least one Al—C bond in the molecule. Among suchcompounds, preferred compounds are those represented by the followingformula,

 R² _(n)AlZ_(3-n)

wherein Al is an aluminum atom, R² is an alkyl group having 1 to 10carbon atoms, Z is a halogen atom or a hydrogen atom, and n is a numbersatisfying 0<n≦3.

Specific examples of the compound represented by the above formula aretrimethylaluminum, triethylaluminum, tri-n-propylaluminum,tri-n-butylaluminum, triisobutylaluminum, tri-tert-butylaluminum,triisopropylaluminum, tripentylaluminum, tri-n-hexylaluminum,tri(2-methylpentyl)aluminum, tri-n-octylaluminum, diethylaluminumhydride, diisobutylaluminum hydride, methylaluminum sesquichloride,ethylaluminum sesquichloride, isobutylaluminum sesquichloride,dimethylaluminum chloride, diethylaluminum chloride, di-n-propylaluminumchloride, di-n-butylmethylaluminum chloride, diisobutylaluminumchloride, di-tert-butylaluminum chloride, diisopropylaluminum chloride,dipentylaluminum chloride, methylaluminum dichloride, ethylaluminumdichloride, isobutylaluminum dichloride, tert-butylaluminum dichloride,isopropylaluminum dichloride and pentylaluminum dichloride. Among these,diethylaluminum chloride, triethylaluminum and triisobutylaluminum aremore preferable.

The organoaluminumoxy compounds used in the present invention may bealuminoxan compounds known in the art. Examples of said compounds arethose obtained by the reaction between one kind of trialkylaluminum andwater, and those obtained by the condensation between two or more kindsof trialkylaluminum and water. Specific examples thereof aremethylaluminoxan, ethylaluminoxan, propylaluminoxan, butylaluminoxan,isobutylaluminoxan, methylethylaluminoxan, methylbutylaluminoxan andmethylisobutylaluminoxan. Of these, methylaluminoxan, isobutylaluminoxanand methylisobutylaluminoxan are particularly preferred.

Production of Olefin Polymer

In producing the olefin polymer, there is no limitation relating to amethod for feeding the solid catalyst component (A) and at least onecompound (B) selected from the group consisting of the organoaluminumcompounds and the organoaluminumoxy compounds to a polymerizationvessel. For example, the feeding of these ingredients can be carried outin a water-free state under atmosphere of an inert gas such as nitrogenand argon in the presence of an olefin monomer to be polymerized. Theingredients, namely the solid catalyst component (A) and the compound(B) may be fed independently of each other to a polymerization vessel,or a contact product between both ingredients may be fed thereto.

An amount of the compound (B) in terms of the aluminum atom containedtherein is usually from 1 to 10000 moles, and preferably from 1 to 3000moles per mole of the transition metal atom in the solid catalystcomponent (A).

In producing the olefin polymer, an additional compound such as a knownelectron donor and hydrogen may be fed at the same time. Preferredelectron donor is, for example, an organic compound having an Si—OR³bond, wherein R³ is a hydrocarbon group having 1 to 20 carbon atoms.Specific examples of the Si—OR³ bond-having organic compound aretetramethoxysilane, dimethyldimethoxysilane, tetraethoxysilane,triethoxysilane, diethoxydiethylsilane, ethoxytriethylsilane,tetraisopropoxysilane, diisopropoxydiisopropylsilane,tetrapropoxysilane, dipropoxydipropylsilane, tetrabutoxysilane,dibutoxydibutylsilane, dicyclopentoxydiethylsilane,diethoxydiphenylsilane, cyclohexyloxytrimethylsilane,phenoxytrimethylsilane, tetraphenoxysilane, triethyoxyphenylsilane,hexamethyldisiloxane, hexaethyldisiloxane, hexapropyldisiloxane,octaethyltrisiloxane, dimethylpolysiloxane, diphenylpolysiloxane,methylhydropolysiloxane and phenylhydropolysiloxane.

In the present invention, besides a contact of the solid catalystcomponent (A) with at least one compound (B) selected from the groupconsisting of the organoaluminum compounds and the organoaluminumoxycompounds, a solid catalyst component (A′), which is obtained bysubjecting the solid catalyst component (A) to pre-polymerizationtreatment, may be brought into contact with the compound (B). Here, the“pre-polymerization treatment” means a treatment to polymerize a smallamount of an olefin on the surface of the solid catalyst component (A).As an example of a process of the pre-polymerization treatment, there isenumerated a process wherein the compound (B) and an olefin are broughtinto contact with the solid catalyst component (A). Such an olefin isnot limited, and examples thereof are ethylene, propylene and butene-1.The olefin may be used singly or in combination of two or more.

The solid catalyst component (A) used for the pre-polymerization is usedpreferably in a slurry state formed through dispersion into a solvent.Examples of the solvent are aliphatic hydrocarbons such as butane,pentane, hexane and heptane, and aromatic hydrocarbons such as tolueneand xylene.

A molar ratio of Al in the compound (B) used for the pre-polymerizationto Ti in the solid catalyst component (A), (Al/Ti), is usually from 0.1to 100, and particularly preferably from 1 to 10. A pre-polymerizationtemperature is usually from −30 to 80° C., and particularly preferablyfrom −10 to 50° C. A polymerization amount of the olefin in thepre-polymerization is usually from 0.1 to 100 g, and particularlypreferably from 0.5 to 50 g per g of the solid catalyst component (A).

As examples of the olefin polymerized according to the presentinvention, olefins having 2 to 20 carbon atoms and diolefins areenumerated. The olefin may be used singly or in combination of two ormore. Specific examples of the olefin are ethylene, propylene, butene-1,pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1,5-methyl-2-pentene-1 and vinylcyclohexene. Examples of the combinationof two or more olefins are ethylene-propylene, ethylene-butene-1,ethylene-hexene-1, ethylene-octene-1 and propylene-butene-1.

Preferred examples of the olefin polymer produced by the presentinvention are ethylene-α-olefin copolymers, and more specifically,ethylene-propylene copolymer, ethylene-butene-1 copolymer,ethylene-hexene-1 copolymer and ethylene-octene-1 copolymer.

In the process for producing the olefin polymer in accordance with thepresent invention, a chain transfer agent such as hydrogen can be fed toa polymerization vessel to regulate a molecular weight of the olefinpolymer to be produced.

A polymerization temperature is usually from −30 to 300° C., preferablyfrom 20 to 250° C., and more preferably from 20 to 100° C., providedthat the temperature is not higher than a melting point of the polymerto be obtained. A polymerization pressure is not limited, and a pressureof from atmospheric pressure to about 150 atm. is preferred fromindustrial and economical points of view. A polymerization time can beappropriately determined depending on the kind of polymer to be obtainedand a reaction apparatus, and usually from 5 minutes to 40 hours.

The polymerization may be carried out in a continuous manner orbatchwise, and a slurry or solvent polymerization with use of an inerthydrocarbon solvent such as propane, pentane, hexane, heptane andoctane, and a liquid or gas phase polymerization with use of no solventcan be applied. Of these, the slurry polymerization and the gas phasepolymerization are particularly suitable.

According to the present invention concerned with the solid catalystcomponent (A-1), there are provided (i) a solid catalyst component forolefin polymerization, (ii) a highly active catalyst for olefinpolymerization, (iii) a process for producing an olefin polymer,particularly a copolymer of ethylene with an α-olefin, and (iv) aprocess for producing a solid catalyst component for olefinpolymerization, according to which an olefin polymer having an extremelylow content of lower molecular weight polymers and/or low crstallinitypolymers, and having superior powder properties can be obtained.

Further, according to the present invention concerned with the solidcatalyst component (A-2), there are provided (i) a solid catalystcomponent for olefin polymerization, (ii) a highly active catalyst forolefin polymerization, (iii) a process for producing an olefin polymer,particularly a copolymer of ethylene with an α-olefin, and (iv) aprocess for producing a solid catalyst component for olefinpolymerization, according to which an olefin polymer having an extremelylow content of lower molecular weight polymers and/or low crstallinitypolymers can be obtained.

EXAMPLE

The present invention is explained in more detail with reference to thefollowing Examples, which are only illustrative and not to be construedto limit the scope of the present invention. The measurement valuesrelating to particulars in Examples were obtained in the followingmanner.

1. Ti Content in Catalyst

Measured according to ICP emission analysis using Optima 3000manufactured by Perkin Elmer Ltd.

2. Content of α-Olefin Unit in Olefin Polymer

Measured from the absorption characteristics of ethylene and theα-olefin using an infrared spectrophotometer, IR-810, manufactured byJapan Spectroscopic Co., Ltd. and expressed in terms of a short chainbranching number (SCB) per 1000 C (carbon atom). The SCB value isincreased with increase of the α-olefin content.

3. Melt Flow Rate (MFR)

Measured at 190° C. according to ASTM D1238.

4. Melt Flow Rate Ratio (MFRR)

MFRR was calculated according to the following equation using the meltflow rate (MFR, load: 2.160 kg) measured at 190° C. according to ASTMD1238 and that (MFR) measured in the same manner, except that the loadwas changed to 21.60 kg:

MFRR=MFR (21.60 kg)/MFR (2.160 kg).

5. Lower Molecular Weight Polymers and/or Low Crystallinity Polymers

Evaluated by a weight of a 20° C. cold xylene-soluble portions (CXS, byweight) in the olefin polymer. In general, the CXS value tends toincrease with increase of the SCB value.

Example 1

(1) Washing of Polymer Particles

In a 200 ml round bottom flask equipped with a stirrer, which flask hadbeen purged with nitrogen gas, 10 g of polymer particles having anaverage particle diameter of 30 μm and a standard deviation of particlediameter distribution of 15.1 μm, and 100 ml of acetone were fed,stirred for 10 minutes at room temperature, and thereafter filtered toseparate polymer particles. The polymer particles used was FLOW BEADS(trade mark), manufactured by Sumitomo Seika Chemicals, Co., i.e.particles of an ethylene-acrylic acid copolymer having an acrylic acidunit content of 7.0% by weight.

The total of the polymer particles separated and 100 ml of acetone wereplaced in the above-mentioned flask and treated in the same manner asabove. The polymer particles separated were dried at 40° C. for 3 hoursunder reduced pressure, thereby recovering the polymer particles in anamount nearly equal to the feeding one. It was found that the polymerparticles maintained their original shape.

(2) Production of Solid Catalyst Component

In a 100 ml round bottom flask equipped with a stirrer, which flask hadbeen thoroughly purged with nitrogen gas, 2.0 g of the polymer particlesobtained in the above (1) and 60 ml of n-heptane were fed. To theresulting mixture was dropwise added 1.1 ml of titanium tetrachlorideunder stirring at room temperature. Thereafter, the mixture was stirredat 40° C. for 1 hour. The reaction mixture obtained was filtered, and asolid separated was washed three times with each 20 ml of hexane. Thesolid washed was dried at room temperature for 2 hours under reducedpressure, thereby obtaining a solid catalyst component (A-1). It wasfound that the solid catalyst component (A-1) had a Ti content of 14.3μmol/g.

(3) Copolymerization of Ethylene With Butene-1

A 400 ml stainless steel-made pressure reaction tube equipped with astirrer, which tube had been thoroughly purged with nitrogen gas, washeld in reduced pressure, and 20 g of butene-1 and 80 g of n-butane werefed therein. Thereafter, the temperature in the system was raised to 70°C., and hydrogen and ethylene were fed therein to obtain hydrogen andethylene pressures of 6.0 kg/cm² and 10 kg/cm², respectively.Thereafter, the mixture was stirred for a while until the system reachedsaturation. Here, the “saturation” means a state at which the gaugepressure of ethylene no longer decreases from the pressure of 10 kg/cm².To the mixture, 2 ml of a heptane solution of trioctylaluminum(concentration: 0.1 mmol/ml) and a liquid prepared by suspending 21.8 mgof the solid catalyst component (A-1) in 5 ml of n-heptane were fed inthis order under pressure of argon gas to initiate polymerization. Onehour after the initiation of polymerization, ethanol was fed in thesystem to discontinue the polymerization, and unreacted gases werepurged to recover a copolymer.

The copolymer was dried at 60° C. for 4 hours under reduced pressure,thereby obtaining 7.6 g of ethylenebutene-1 copolymer. With respect tothe copolymer obtained, SCB, MFR, MFRR and CXS were found to be 18.4(/1000 C), 0.45 (g/10 min.), 39.6 and 4.3% by weight, respectively.

Example 2

(1) Washing of Polymer Particles

Example 1 (1) was repeated, except that the polymer particles having astandard deviation of particle diameter distribution of 15.1 μm wasreplaced by polymer particles having a standard deviation of particlediameter distribution of 8.3 μm. As a result, the polymer particles wererecovered in an amount nearly equal to the feeding one, and it was foundthat the polymer particles maintained their original shape.

(2) Production of Solid Catalyst Component

In a 500 ml round bottom flask equipped with a stirrer, which flask hadbeen thoroughly purged with nitrogen gas, 200 ml of heptane and 48.1 mlof 2-tert-butylphenol were fed, and heated to 40° C. under stirring. Tothe mixture was dropwise added a solution composed of 17.6 ml oftitanium tetrachloride and 80 ml of heptane over 70 minutes. Thereafter,the mixture was further heated to 60° C., and then allowed to react withone another for 2 hours. After the reaction was over, the solvent wasevaporated at 120° C. to obtain a dried reaction product. The driedproduct was washed two times with each 200 ml of hexane, and the productwashed was dried at 120° C. for 30 minutes, and thereafter cooled toroom temperature, thereby obtaining a solid component.

In a 300 ml round bottom flask equipped with a stirrer, which flask hadbeen thoroughly purged with nitrogen gas, 37.5 g (90 mmol in terms oftitanium atom) of the solid component obtained above and 180 ml ofheptane were fed to form a slurry of the solid component. To theresultant were added 18 g of the polymer particles obtained in the above(1) and 10 ml of n-heptane, and the resulting mixture was allowed toreact with one another at 40° C. for 1 hour under stirring. The reactionmixture obtained was filtered, and a solid separated was washed threetimes with each 20 ml of hexane. The solid washed was dried at roomtemperature for 2 hours under reduced pressure, thereby obtaining asolid catalyst component (A-2). It was found that the solid catalystcomponent (A-2) had a Ti content of 22.9 μmol/g.

(3) Copolymerization of Ethylene with Butene-1

Example 1 (3) was repeated, except that the solid catalyst component(A-1) was replaced by the solid catalyst component (A-2), therebyobtaining 14.4 g of a dried ethylene-butene-1 copolymer. With respect tothe copolymer obtained, SCB, MFR and MFRR were found to be 15.6 (/1000C), 0.54 (g/10 min.) and 24.7, respectively, and CXS was not more thanthe limit of detection.

What is claimed is:
 1. A catalyst for olefin polymerization, which isobtained by a process comprising the step of contacting: (A-1) a solidcatalyst component for olefin polymerization, which is obtained by aprocess comprising the step of contacting: (a-1) a carrier of carboxylgroup-carrying polymer particles having an average particle diameter offrom 1 to 300 μm, and (b) a transition metal compound of the number 4group of metals in the periodic table of elements, and (B) at least onecompound selected from the group consisting of organoaluminum compoundsand organoaluminumoxy compounds, wherein said process does not use anorganometal compound of a metal of groups 1, 2, or
 13. 2. A process forproducing an olefin polymer, which comprises the step of polymerizing anolefin in the presence of a catalyst for olefin polymerization, whichcatalyst is obtained by a process comprising the step of contacting:(A-1) a solid catalyst component for olefin polymerization, which isobtained by a process comprising the step of contacting: (a-1) a carrierof carboxyl group-carrying polymer particles having an average particlediameter of from 1 to 300 μm, and (b) a transition metal compound of thenumber 4 group of metals in the periodic table of elements, and (B) atleast one compound selected from the group consisting of organoaluminumcompounds and organoaluminumoxy compounds, wherein said process does notuse an organometal compound of a metal of groups 1, 2, or
 13. 3. Theprocess for producing an olefin polymer according to claim 2, whereinthe olefin polymer comprises ethylene units and α-olefin units.
 4. Acatalyst for olefin polymerization, which is obtained by a processcomprising the step of contacting: (A-2) a solid catalyst component forolefin polymerization, which is obtained by a process comprising thestep of contacting: (a-2) a carboxyl group-carrying polymer carrier, (b)a transition metal compound of the number 4 group of metals in theperiodic table of elements, and (c) a phenol compound, and (B) at leastone compound selected from the group consisting of organoaluminumcompounds and organoaluminumoxy compounds, wherein said process does notuse an organometal compound of a metal of groups 1, 2, or
 13. 5. Aprocess for producing an olefin polymer, which comprises the step ofpolymerizing an olefin in the presence of a catalyst for olefinpolymerization, which catalyst is obtained by a process comprising thestep of contacting: (A-2) a solid catalyst component for olefinpolymerization, which is obtained by a process comprising the step ofcontacting: (a-2) a carboxyl group-carrying polymer carrier, (b) atransition metal compound of the number 4 group of metals in theperiodic table of elements, and (c) a phenol compound, and (B) at leastone compound selected from the group consisting of organoaluminumcompounds and organoaluminumoxy compounds, wherein said process does notuse an organometal compound of a metal of groups 1, 2, or
 13. 6. Theprocess for producing an olefin polymer according to claim 5, whereinthe olefin polymer comprises ethylene units and (α-olefin units.